Multihole fuel injection nozzle

ABSTRACT

A fuel injection nozzle is disclosed in which a plurality of orifices or nozzle holes are formed through a nozzle head in such a way that the angles of spray are increased stepwise as the orifices are farther located from the center of the nozzle tip. The orifices may be arrayed in row or column or along one or a plurality of coaxial circles. The fuel-air or steam mixtures injected through the orifices will not interfere with each other so that a large number of independent small flames may be formed.

United States Patent [191 Tsuji [4 1 Oct. 21, 1975 1 MULTIHOLE FUEL INJECTION NOZZLE [75] Inventor:

[73] Assignee: Ishikawajima-Harima Jukogyo Kabushiki Kaisha, Tokyo, Japan [22] Filed: Oct. 25, 1973 [21] Appl. No.: 405,558

Shoichi Tsuji, Hoya, Japan [30] Foreign Application Priority Data [56] References Cited UNITED STATES PATENTS 598,873 2/1898 Joy 239/557 X 724,008 3/1903 Higgins 23 /429 Lassoe et al. 239/433 X 981,011 1/1911 Schuchardt 239/556 X 1,062,714 5/1913 Johnston 239/559 X 1,823,635 9/1931 Williams 239/558 1,870,066 8/1932 Olson 239/567 X 2,254,751 9/1941 Paradisem. 239/559 2,518,543 8/1950 I-Iasse 239/553.3 2,933,259 4/1960 Raskin 239/559 X 3,047,241 7/1962 McLhinney 239/567 X FOREIGN PATENTS OR APPLICATIONS 1,446,439 6/1966 France 239/567 Primary ExaminerR0bert S. Ward, Jr.

[57] ABSTRACT A fuel injection nozzle is disclosed in which a plurality of orifices or nozzle holes are formed through a nozzle head in such a way that the angles of spray are increased stepwise as the orifices are farther located from the center of the nozzle tip. The orifices may be arrayed in row or column or along one or a plurality of coaxial circles. The fuel-air or steam mixtures injected through the orifices will not interfere with each other so that a large number of independent small flames may be formed.

2 Claims, 7 Drawing Figures US. Patent Oct. 21, 1975 SheetlofZ 3,913,845

o 6D I o 60 I \L O O I US. Patent Oct. 21, 1975 511m 2 of2 3,913,845

MULTIHOLE FUEL INJECTION NOZZLE The present invention relates to a fuel injection nozzle.

In the conventional fuel gas injection nozzles and liquid fuel injection nozzles of the type in which the liquid fuel is mixed with air or steam within a mixing chamber in the nozzle and injected through the orifices to be atomized and sprayed into the combustion chamber, a plurality of orifices have the same angle of spray, that is the angle between the axis of the orifice and the axis of the nozzle, so that the fuel-air or steam mixtures injected through the orifices interfer with each other and form a single spray pattern. As a result a large and single flame is formed so that the surface area of the flame is smaller as compared with the volume. Therefore the radiation from the flame is less so that the temperature of the flame is high with the result of the increase in quantity of nitrogen oxides.

One of the objects of the present invention is therefore to eliminate the above problem of the conventional liquid fuel and fuel gas injection nozzles.

Another object of the present invention is to provide a fuel injection nozzle in which a plurality of orifices are so formed that the injected fuel gas or fuel-air or steam mixtures will not interfere with each other, whereby the heat radiation from the small flames may be considerably increased to reduce the temperatures of the flames and to suppress the production of nitrogen oxides.

The above and other objects, features and advantages of the present invention will become more apparent from the following description of preferred embodiments thereof taken in conjunction with the accompanying drawing.

FIG. 1 is a sectional view of a first embodiment of the present invention;

FIG. 2 is a side view thereof;

FIG. 3 is a side view of a variation thereof;

FIG. 4 is a sectional view of a second embodiment,

FIG. 5 is a side view thereof,

FIG. 6 is a sectional view of a third embodiment of the present invention; and

FIG. 7 is a side view thereof.

First embodiment is shown in FIGS. 1, 2 and 3.

Referring to FIG. 1, a nozzle tip 4 in the form of a hollow box is securely joined to a nozzle holder 1. A fuel passage 2 which is formed in the nozzle holder 1 along the axis thereof is communicated through a fuel port 2a with a fuel-air mixing chamber 5 formed within the nozzle tip 4. Air passages 3 formed within the nozzle holder 1 around the fuel passage 2 are also communicated with air ports 3a with the mixing chamber 5.

A plurality of orifices or nozzle holes 6a, 6b, 6c and 6d are formed in the nozzle tip 4 vertically in line with each other, and the angles of the axes of the orifices 6a, 6b, 6c and 6d with respect to the axis of the nozzle holder 1 have the following relation:

As shown in FIG. 3, the orifices 6 may be formed in two columns or a plurality of orifice columns may be formed. Alternatively the orifices may be arrayed in a zig-zag form. Furthermore the nozzle tip 4 may be cylindrical or in any suitable shape.

The second embodiment shown in.FIGS. 4 and is different from the first embodiment described hereinbefore with reference to FIGS. 1, 2 and 3 is that the nozzle tip is cylindrical and the orifices 6 are formed through the side wall thereof. The angles of spray between the axis 0 of the cylindrical nozzle tip 4 and the axes of the orifices 6 are such that In other words, the angle 0 of the axis of the orifice closest to the point 4 at which the axis 0 intersects the top surface of the cylindrical nozzle tip 4 and the axis 0 is smallest, and the angle 0 of the orifice 6b second closest to the point 4 is greater than the angle 6 of the orifice 6a. In like manner the angle of one orifice is greater than the angle of an adjacent orifice closer to the point 4'.

In the second embodiment, the nozzle tip 4 is shown as having the upper and lower orifice rows, but it will be understood that a plurality of orifice rows may be formed or a plurality of orifices may be arrayed in zigzag form or in any other suitable pattern. Furthermore instead of the cylindrical nozzle tip 4, a nozzle tip in any suitable shape may be used.

In the first and second embodiments, the fuel is supplied into the mixing chamber 5 through the fuel passage 2 and the fuel port 2a, and air or steam is supplied into the mixing chamber through the air passages 3 and ports 3a. In the mixing chamber the fuel and the air or steam are mixed and finely divided, and the atomized fuel-air mixture is sprayed through the orifices 6 into a combustion chamber. Since the angles of the orifices 6 are different from each other, the injected fuel-air mixtures will not interfer with each other so that a large number of independent small flames may be formed.

Next referring to FIGS. 6 and 7, the third embodiment of the present invention will be described hereinafter. The fuel injection nozzle comprises a nozzle holder 21, a guide ring 24, a nozzle tip 25, and a socket 26. A fuel passage 22 is formed in the nozzle holder 21 along the axis thereof, and air or steam passages 23 are also formed within the nozzle holder 21 and around the fuel passage 22. The guide ring 24 has an fuel port 22a and air or steam ports 23a communicating the fuel passage 22 and the air or stream passages 23, respectively, with a mixing chamber 29 in the nozzle tip 25. The front end portion or nozzle tip N extending beyond the socket 26 of the nozzle tip 25 is semispherical and has two coaxial rows 27 and 28 of equiangularly spaced apart orifices. The nozzle holder 21, the guide ring 24 and the nozzle tip 25 are assembled air-tightly by the socket 26 which is screwed over the nozzle holder 21.

Four orifices 27 are formed along a circle, whose center axis 0 of the fuel injection nozzle, and are spaced apart equiangularly. In like manner, the orifices 28 are formed in equiangularly spaced apart relation, but are staggered with respect to the orifices 27. The angle 0 between the axis of each orifice 27 and the axis 0 is smaller than the angle 0 between the axis of each of the outer orifices 28 and the axis 0.

The fuel and air or steam are through the fuel passage 22, the air or steam passages 23, the fuel port 22a and the air or steam ports 23a into the mixing chamber 29, and the fuel-air or steam mixtures are injected through the orifices 27 and 28 into a combustion chamber. Since the angles 0 and 0 of the orifices 27 and 28 are different and the orifices 27 and 28 are staggered from each other, the injected fuel-air or -steam mixtures will not interfer with each other so that a large number of independent flames may be formed.

In the embodiments described hereinbefore, the liquid fuel is mixed with air or steam to be injected into the combustion chamber, but it will be understood that the fuel injection nozzle of the present invention is also used to inject fuel gas. When fuel gas is used, it is of course not necessary to provide the air or steam passages and ports so that the gas fuel injection nozzles of the present invention may be much simplified in con struction.

When the fuel injection nozzle of the present invention is used, a large number of independent small flames are formed so that the overall surface area of the flames is much larger than that of a single flame produced by the conventional multihole fuel injection nozzle. As a result, the heat radiation from the flames is considerably increased so that the temperatures of the flames are reduced. Therefore the complete combustion at a relatively low temperature may be ensured, and the emission of nitrogen oxides may be substantially eliminated or reduced. Furthermore the time when the combustion products remain in the small flame is shorter than in the large flame so that the production of nitrogen oxides may be considerably suppressed.

What is claimed is:

l. A fuel injection nozzle comprising a hollow elongated cylindrical head, said head having one open end and one closed end and at least one row of longitudinally spaced discharge openings extending through its wall, each of said openings extending at an angle to the axis of said head, with the angles decreasing in propor tion to the respective distances of said openings from said open end, and means registering with said open end for supplying a combustible fuel to said hollow portion for discharge through said openings.

2. The nozzle of claim 1 wherein there are two diametrically opposed rows of said openings extending through said wall. 

1. A fuel injection nozzle comprising a hollow elongated cylindrical head, said head having one open end and one closed end and at least one row of longitudinally spaced discharge openings extending through its wall, each of said openings extending at an angle to the axis of said head, with the angles decreasing in proportion to the respective distances of said openings from said open end, and means registering with said open end for supplying a combustible fuel to said hollow portion for discharge through said openings.
 2. The nozzle of claim 1 wherein there are two diametrically opposed rows of said openings extending through said wall. 